1. Field of the Invention
The invention relates to input displays, and in particular to light input displays having convex lenses for converging light onto the light sensitive elements, enhancing sensitivity thereof.
2. Description of the Related Art
With an input display, a user can select from displayed options by touching the option directly. Common techniques employed in an input display for detecting the location of a touch include infrared light, surface acoustic waves, optical sensing, electromagnetic sensing, capacitance sensing and resistor sensing.
Input displays comprise a touch panel supported above a glass screen of the displays to detect touch position, increasing the cost of the display, and reducing transmittance by about 20%. Embedded optical input displays use the optical sensitivity of amorphous silicon to integrate photo thin-film transistor (photo-TFT) into array processes of thin-film transistor liquid crystal displays (TFT-LCD). Thus, the cost of embedded optical touch panel is lower and optical performance is better.
Traditional color filters of LCD comprise red, green and blue (RGB) color filters. Photo TFTs of traditional embedded optical input displays are disposed corresponding to the blue color filters, because influence of blue light on human eye and brightness of blue light are less than those of red and green light. Recently, some techniques have changed color filters from RGB to red, green, blue and white (RGBW) for enhanced resolution and brightness of small panels.
FIG. 1 is a cross section of a conventional embedded optical input displays with color filters of RGBW type. Red 140, green 160, blue 180 and white 210 color filters are surrounded by a black matrix 120. Specially, the white color filter 210 is formed by a transparent layer for keeping a uniformity of cell gap. Photo TFTs 260 are disposed on the lower substrate 300 facing the upper substrate 100 corresponding to the white color filter 210 for receiving light passing through the transparent layer. To complete an input display, the upper substrate 100 and lower substrate 300 are assembled, and a liquid crystal layer 360 is filled between the upper substrate 100 and lower substrate 300. A seal 340 is disposed between the upper and lower substrate to seal the input display. The surface curvature of the white color filter 210 is too small and a central axis 290 of the transparent layer is not aligned to photo TFT 260, limiting the light received by photo TFT, and thus diminishing the sensitivity of optical input display.
Thus, it is desirable to provide an input display which can converge more light onto photo TFTs to enhance sensitivity of the input display.